Centrifugal fan.



E. B'. WILLIAMS.

CENTRIFUGAL FAN.

APPLICATION FILED 110v.2o,19o9.

LGQGQ, Patented Apr. 22, 1913.l

,e the wheel. lhe linner edges 1.2of the blades at the rear of the `hub l are preferably inclined outward fron the hub toward the rear. plate l1, since it has been found that this construction enables the blades to act 'e'iiiciently upon the 'air with less expenditure of power than would otherwise be required. The rear side f the casing is preferably provided with an inwardly projecting plate 13 which substantiallv fills the frusto conical space Within the blades back of the hiiib 4. This plate Spr-events the accuinulation of matter Within the` blades at the rear side of the hub, such as might clog and interfere with the rot-ation of the fan Wheel.

Having explained the nature and object of the invention, and specifically described one form of fan in which' it may be ernbodied, what I claim is 1. centrifugal fan, having, in combination, a scroll casing provided with an axial inlet eye and a tangential outlet, a Wheel Within the easing provided with radially eX- tending blades having their inner edges inclined from the outer ends of the blades to- Ward the axis to form a frusto conical inletchamber thc larger diameter of which is substantially the diameter of theeyie, and radially extending ribs on the Working faces of each blade the outer one of which intersects the inclined edge near the inner end of the frusto conical chamber, substantially as described.

2. A centrifugal. fan having, in combination, ascroll casing provided with an axial inlet eye and a tangential outlet, a Wheel mounted within the casing concentric with Vthe eye and consisting of a central hub 4, a series of radially extendiiig arms 6,blades 5 secured to the ends of the arms and provided with inclined inner edges 7, the outer endsv 8 of the blades being substantially in line with the inlet eye, corrugations in the blades forming radial ribs 9 which intersect the inclined edges 7 in .front of thel radial arms and also forming radial ribs 10 intersecting the edges of the blades at the rear of the radial arms, and a frear plate 11 secured to the rear edges'of the blades, substantially as described.

EUGENE B. WILLIAMS.

Witnesses M. L. GILMAN, N. D. MCPHML. 

